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MANAGEMENT PLAN
PREVENTION AND MANAGEMENT OF BLAST GENERATED NOx
Tata Steel Minerals Canada Ltd.
Direct Shipping Ore Project
November 2015
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Table of Contents page
1. Purpose ........................................................................................................................................ 1
2. Scope ............................................................................................................................................ 1
3. Background .................................................................................................................................. 1
3.1 Requirement for a Blast Generated NOx Management Strategy ........................................................ 1 3.2 Theory – NOx in Blast Fumes ............................................................................................................. 1 3.3 Causes of NOx Gases in Blasting ....................................................................................................... 2
4. Management Procedures............................................................................................................. 3
4.1 Blast Design by Explosives/Precursor Manufacturer/Supplier ............................................................ 3 4.2 Pre-Blast Environmental Assessment ................................................................................................. 3 4.3 Pre-Blast and Post-Blast Checklist ...................................................................................................... 3 4.4 Blast Log .............................................................................................................................................. 4
5. Documentation and Retroaction ................................................................................................. 6
5.1 Documentation ..................................................................................................................................... 6 5.2 Retroaction .......................................................................................................................................... 6
Appendices
Appendix A Blast Design Datasheet
Appendix B Pre-Blast Environmental Assessment List Appendix C Pre-Blast / Post-Blast Checklist Appendix D Blast Log
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1. Purpose
This procedure outlines responsibilities and guidelines for manage and assist in the minimisation and management
of blast fumes, in particular oxides of nitrogen (NOx) at the Direct Shipping Ore (DSO) Project operated by Tata
Steel Minerals Canada Ltd., near Schefferville, QC.
2. Scope
Those involved in blasting operations need to be aware of the causes, risks and consequences of the oxide of
nitrogen (NOx) gases that may emanate from their blasting activities. The aim of this Plan is to provide information
and recommended guidelines to assist in the prevention and management of blast generated NOx gases from
surface blasting operations. The Plan is specific to NOx gases and covers the following areas:
the likely causes of NOx gases from blasting
possible control measures to prevent or minimise blast generated NOx gases
management of NOx gases from blasting should they occur
This document provides a mitigation strategy based on the Code of Practice for Prevention and Management of
Blast Generated NOx Gases in Surface Blasting established by the Australian Explosives Industry and Safety Group
(AEISG) (Edition 2, August 2011)1.
3. Background
3.1 Requirement for a Blast Generated NOx Management Strategy
Air quality studies conducted by TSMC in the context Environmental Impact Assessments for Provincial and Federal
authorities show that air emissions (such as dust, NOx, CO and SO2) generated during blasting events can negatively
affect the air quality in the vicinity of the pits where blasting is conducted.
As part of an EIA submitted to the Canadian Environmental Assessment Agency (CEAA) in the fall of 2015 for the
Howse Property Project (HPP), TSMC has committed to the development and implementation of a Plan for the
prevention and management of blast generated NOx. This Plan will be put into effect when blasting at the HPP
starts. This plan is applicable to blasting at the following pits: Howse, Fleming 7N and Timmins 3N. However, its
application will be extended to other active pits as deemed necessary.
3.2 Theory – NOx in Blast Fumes
The group of gases known as Oxides of Nitrogen or NOx, of which the most common are nitric oxide (NO) and
nitrogen dioxide (NO2), are often found as by-products in the post-blast gases of ammonium nitrate-based
explosives. Together, these gases are loosely referred to as “NOx”. Nitric oxide is invisible, but nitrogen dioxide
ranges from yellow to dark red depending on the concentration and size of the gas cloud. These gases are
pollutants. NOx from blasting constitutes only a small proportion of the total NOx emissions from human activities
1 http://www.aeisg.org.au/images/stories/aeisg_cop_nox_edition_02aug2011.pdf
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(primarily power generation and motor vehicles) and natural sources. However blasting produces a sudden
localised release of gases with potentially high concentrations of NOx. Such gas emissions pose a health risk if
people are exposed to them before the plumes can dissipate.
Despite a long history of blast-related NOx emissions, very few quantitative studies have been done under realistic
field conditions. The underlying causes of high NOx are fuel-deficiency in the explosive or detonation reactions that
do not continue to completion. There are many ways in which these conditions may arise.
In the absence of a single general cause or general solution, this Plan was developed by TSMC as an aid to
identifying the local cause of NOx and as a prompt for possible ways to address those causes. It should be
understood that, given the complexity of the problem and the inherent variability in the blasting environment, NOx
events may still occur even after prevention and mitigating actions have been put in place. The Plan therefore
include advice on managing blasts that could produce NOx gases.
3.3 Causes of NOx Gases in Blasting
The post-blast gases and fumes are generated as a result of the ammonium nitrate-based explosive detonation at
the blast site. The factors that trigger the formation of the NOx are various but the following factors are among the
main contributors in the generation of post-blast fumes during the mining process:
Explosive formulation and quality assurance; Geological Conditions; Climate/seasonality; Blast design; Explosive product selection; Contamination of explosive in the blast-hole; On-bench practices.
Section 5 of the Code of Practice for Prevention and Management of Blast Generated NOx Gases in Surface
Blasting should be consulted as an aid to identifying causes and mitigation measures.
As a result, the formation of the toxic fumes can be managed through some preventive controls considering the
geological conditions during the design phase, designing an appropriate design for the blast, selecting an
appropriate product formulation for the detonation, considering the weather condition during the time of loading;
implementing on-bench practiced to minimise the potentials for water ingress into blasting area; minimising the
contamination of explosives in blast holes.
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4. Management Procedures
4.1 Blast Design by Explosives/Precursor Manufacturer/Supplier
The manufacturer and/or supplier of the precursors or bulk explosives must ensure products are formulated appropriately to prevent/minimise the generation of NOx gases during blasting. The products should be authorised, with quality control systems in place to ensure that the manufactured/supplied products meet specifications. For each blast, a copy of the Blast Design datasheet must be forwarded to TSMC on-site Environmental team. An example “Blast Design” datasheet is provided in Appendix A of this Plan. The explosives manufacturer/supplier must provide documentation for modification and alterations to explosive and/or precursor formulations. Documentation must be provided to TSMC on-site Environmental team and must cover the following aspects:
1. recording any modification/alteration and updating relevant authorisations, Technical Data Sheets, Material Safety Data Sheets, work procedures, and training programs as and where relevant;
2. ensuring changes continue to meet the requirements of this Code;
4.2 Pre-Blast Environmental Assessment
In collaboration with the blasting manager, TSMC on-site Environmental team will complete a Pre-Blast Environmental Assessment. A copy of the Pre-Blast Environmental Assessment list is provided in Appendix B. The assessment covers 6 criteria:
Explosive Formulation and Quality Assurance Geological conditions Blast Design Explosive product selection On bench practices Contamination of explosives in the blast hole
The assessment may be conducted days before a blasting event is scheduled.
4.3 Pre-Blast and Post-Blast Checklist
Appendix C contains an example of the Pre-Blast / Post-Blast checklist, currently in use at the site. The Pre-Blast / Post-Blast checklist The following parameters will be added to the Pre-Blast section of the checklist:
a) Acknowledgement of the Environmental Assessment by the responsible for drilling and blasting b) Meteorological conditions: wind speed, wind direction, temperature, precipitation c) For pits located in the vicinity of the Workers’ camp (ex.: Howse, Fleming 7N, Timmins 3N) , blasting must
be conducted while the wind is NOT blowing in direction of the Workers’ camp The following parameters will be added to the Post-Blast section of the checklist:
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a) Visual Rating Scale: Assessment of the Post-Blast fume should using the AEISG visual NOx fume rating
scale. b) duration of any post-blast NOx gas event;
c) direction of movement of any post-blast NOx plume;
d) movement of any post-blast NOx gas plume relative to the established exclusion zone and any established
management zone;
e) results/readings of any NOx monitoring equipment employed for the blast;
f) video results of blasts where relevant
4.4 Blast Log
Appendix D contains an example of the Blast Log used for recording blasting events. This information log will continue to be used at the site for all blasts.
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5. Documentation and Retroaction
5.1 Documentation
For each blast, the following documents will be reviewed and filed by TSMC on-site environmental team:
a) Blast Design by blasting company or responsible b) Pre-Blast Environmental Assessment c) Pre-Blast and Post-Blast Checklist d) Blast Log
5.2 Retroaction
Any reported significant NOx event or trends should be investigated to minimize the potential for ongoing generation of NOx gases and to mitigate the potential impacts of any such event. Such investigation should involve the explosives manufacturer and/or supplier. The fault tree (see Section 6 Code of Practice for Prevention and Management of Blast Generated NOx Gases in Surface Blasting) should assist any investigation and ensure all relevant factors are considered and adequately addressed. The results of any investigation of post-blast NOx gases should then be factored into the site specific procedures to minimize their production and to mitigate impacts.
Appendix A
Blast Design Datasheet Example Datasheet Currently in Use. To Be Amended As Per This Plan.
Pre-Blast Environmental Assessment TSMC DSO - SCHEFFERVILLE
Blast #: Pit ID:
Scheduled Blast Date:
Assessed by: Assessement Date:
Assessment Criteria Likelihood Notes
PB 1: Explosive Formulation and Quality Assurance
Explosive product incorrectly formulated
Explosives product change
Inadequate mixing of raw materials
Delivery system metering incorrectly
Delivery system settings for explosive product delivery overridden
Explosive precursors not manufactured to specification
Precursor degradation during transport and storage
Raw material changes
Other:
PB 2: Geological conditions
Lack of relief in weak/soft strata
Inadequate confinement in soft ground
Explosive product seeping into cracks
Dynamic water in holes
Moisture in clay
Blast hole wall deterioration between drilling and loading eg cracks, voids, hole contraction
Chemistry of rock type e.g. limestone
Other:
PB 3: Blast Design
Explosive desensitisation due to the blast hole depth
Inappropriate priming and/or placement
Mismatch of explosives and rock type
Inter-hole explosive desensitisation
Intra-hole explosive desensitisation in decked blast holes
Initiation of significant explosive quantities in a single blast event
Other:
PB 4: Explosive product selection
Non water-resistant explosive products loaded into wet or dewatered holes
Excessive energy in weak/soft strata desensitising adjacent explosive product columns
Primer of insufficient strength to initiate explosive column
Desensitisation of explosive column from in-hole cord initiation
Inappropriate explosive product for application
Other:
PB 5: On bench practices
Hole condition incorrectly identified
Blast not drilled as per plan
Dewatering of holes diverts water into holes previously loaded with dry hole explosive products
Blast not loaded as per blast plan
Other:
PB 6: Contamination of explosives in the blast hole
Explosive product mixes with mud/sediment at bottom of hole.
Interaction of explosive product with drilling muds.
Penetration of stemming material into top of explosive column (fluid/pumpable explosive products only)
Water entrainment in explosive product
Moisture in ground attacking explosive product
Contamination of explosives column by drill cuttings during loading
Rainfall on a sleeping shot.
Other:
Appendix C
Pre-Blast / Post-Blast Checklist Example checklist Currently in Use. To Be Amended As Per This Plan.
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